Improvement in the manufacture of lime and cement



J. K. SHINN. Manufacture of Lime and Cement.

N o. ZI7 QIF Patnted July 8,1879.

kilns and others in addition.

UNITE STATES PATENT Ont-Ion JonN K. SHINN, on NEW cAsrtE, PENNSYLVANIA.

, IMPFOVEMENT IN THE, MANUFACTURE OF LI'ME AND CEMENT.

. Specification forming part of Letters Patent No. 217,415, dated July8, 1879; application filed November 1, 1878.

To all whom it may concern:

Be it known that 1, JOHN K. SHINN, of Newcastle, in the county ofLawrence and State of Pennsylvania, have invented certain new and usefulImprovements in the Manufacture of Lime and Cement; and I do herebydeclare the following to be a full, clear, and exact de scription of theinvention, such as will enable others skilled in the artto which itpertains to make and use it, reference being bad to the accompanyingdrawings, which form part of this specification, in which- Figures 1 and2 are, respectively, elevation and plan of a cement-furnace after myinvention. Figs. 3 and at are vertical and horizontal sections,respectively, of a limekiln with my improvements.

In limekilns it is next to impossible to obtain regularity of product.The operation of burning is slow and unnecessarily expensive. Thelimestone burns irregularly, pieces of half'burned stone coming downprematurelyto the bottom, where no sufficient heat exists to completethe burning; consequently the product is more or less irregular, andnever absolutely reliable unless tested or selected for use.

Similar disadvantages are found in cement- Oement requires rapidcombustion, which cannot properly be secured by means at present in usein kilns. Failing to get the required rapidity, the material dustst'.6., crumbles into powder--be cause the draft is insufficient to quicklycool the lower portions as the combustion proceeds upwardly; hence thematerial remains in its own heat too long, the hard cinder desiredcrumbles into dust, impedes the draft still more, thus interfering moreand more with the combustion of the remainder of the charge, causing theproportionate amount of dusting to constantly increase. The result ofall this, and of the further dusting after burning is completed, causedby the slow cooling of this air-excluding compacted mass, is thatfifty-per cent. of possible product is lostin the process.

I propose to surmount all the above difficulties by my invention, whichconsists in injecting a forced draft into the lower part of the kiln,operating or utilizing said draft in the first or burning stage topromote combustion,

and then continuing the same for the purpose of effecting the cooling ofthe contents of the kiln, the application and operation being as Myinvention embodies not only the forced draft for rapid combustion, butalso the continuation of such forced draft to effect rapid cooling.

A designates a cementkiln of the ordinary pattern, having thecombustion-chamber B and eye 0. D is'a blower or other device forinjecting a forced blast, having the pipe 01 for kiln is charged, firestarted, and the eye bricked up, having the pipe d passing through it,as shown. The blower is operated and the blast is continuouslymaintained until the charge is thoroughly burned, and then withoutceasing until the charge of cement-cinder is completely cooled.

Results: The draft being uniform and of the required energy, thematerial burns more rapidly and more regularly; dusting or slaking isabsolutely prevented, what material would otherwise dust being preservedin true cement cinder; the burning is completed much sooner; the productis more uniform and perfect, and the yield is fifty per cent. greater.necessary to dwell on the value of such results to cement-makers. Timeand fuel are saved in the burning, time of cooling lessened, and bothquantity and quality of product largely improved.

I modify the arrangement somewhat for burninglimestone. E designates alimekiln of ordinary form, having combustion-chamber F and eye G. H ismy draft-forcing apparatus, leading the blast into a supply-pipe, e,which is so arranged as to send at will the blast or through thetuycre-pipes g and tuyeres h,

thorough, leaves no half-burned ston e,and when all combustible materialis burned the blast is follows reference bein had'to the drawin s.

conveying the blast through the eye 0. The

It is unthrough pipe f, projecting through the eye G,

disposed at a suitable point higher up. Fire maintained in order torapidly cool the lime. All the fuel is consumed, the stone is properly,because thoroughly, burned, and the result is a superior and uniformquality of lime. I am Well aware that it is not new in kilns to employ aforced blast to promote combustion; nor do I lay claim, broadly, to thecm ployincnt of a blast for cooling the material as it falls from thekiln My invention, however, has reference to kilns in which the materialis burned inlayers, and particularly to the burning of Portland cement,and consists in the employment and continuation of the one forced blast,both for promoting the combustion and afterward effecting the cooling ofthe burned material.

I claim as my invention- 1. The herein-described process of rapidlyproducing lime and cement, consisting in subjecting the raw materialwhile hurnin g to the action of a forced blast, continuing the sameuntil burning is completed, and then sustaining the forced blast toeffect rapid cooling, substantially as described.

2. A kiln provided with tuyeres above and a blast-pipe below thegratebars, in combination with a blast-forcing apparatus constructed andarranged substantially as set forth, whereby it may be interchangeablycon nected with either tuyeres or blast-pipe at will, substantially asdescribed.

In testimony that I claim the foregoing I have hereunto set my hand this23d day of October, 1878.

JOHN K. SHINN. NVitnesses:

GEO. W. VEAGH, A. L. HAZEN.

